Television picture tubes



March 18, 1958 v as 13 'R 58 ii R. H. OLSON TELEVISION PICTURE TUBES Filed July 9, 1953 INVENTOR Kr: LPHH. 055011 I MQ W,

ATTORNEY5,

rnLnvrsroN PHITURE TUBES Ralph Harvard Olson, Toledo, Ghio, assignor to Owenslllinois Glass (Iompany, a corporation of Ghio Application July 9, 1953, Serial No. 366,996

13 Claims. (Ci. 313-64) l -y invention relates to constructional features of television picture tubes and is of special utility a embodied in color television tubes, the invention being herein illustrated and described as so used, although not limited to tubes for color television.

The invention is herein shown as applied to a tube of the type comprising a funnel-shaped body or shell, made of glass or metal, and a face plate made of glass or transparent material and hermetically sealed to the large end of the funnel. Picture tubes for color television television ordinarily include a grid assembly or element commonly known as a sandwich, which is mounted at the front or face plate end of the tube. This sandwich, which includes a color grid or mask formed with multiplicity of small perforations through which the electron beams are directed to a sensitized grid or phosphors, must be accurately aligned with the central axis of the tube and rigidly held in position. Obviously, this sandwich must be installed before the face plate and funnel are joined together.

in methods in use at the present day for uniting and sealing the face plate and body shell, high temperatures are employed which are sometimes ruinous to the enclosed grid assembly or cause distortion and misalignment which render the tube inoperative or useless. Also, the parts may be thrown out of adjustment during the process of uniting the face plate with the funnel.

Experience has demonstrated that owing to one cause or another, a considerable percentage of the assembled tubes are unsatisfactory and must be opened for further adjustments. Thi makes it desirable to provide a construction or means by which, if necessary, the face plate can be removed to permit readjustment of parts and thereafter resealed to the funnel at a minimum of trouble and expense.

An object of the present invention is to provide a novel and practical construction which will permit removal and rescaling of the face plate. The invention provides novel means for attaching and sealing the face plate at temperatures below the maximum temperature to which the sandwich or enclosed parts can be subjected without injury or detrimental effects. A further feature of the invention consists of providing a novel construction and means for joining the face plate to the funnel which is capable of withstanding external pressures resulting from having the tube evacuated and which also will provide a perfect hermetic seal, preventing leakage of gases into the tube.

A further object of the invention is to provide a construction which is practical and economical and in which the processes of manufacture and assembly can be carried out with ordinary and practical production methods and with a low percentage of unsatisfactory parts.

Other objects will appear hereinafter.

The invention in its preferred form comprises a funnelshaped body or shell in which is mounted an annular supporting frame for the sandwich, said frame being formed to fit over the rim of the funnel and comprising an ice exterior cylindrical flange portion surrounding and adapted to be hermetically sealed to the exterior surface of the rim of the funnel. The face plate is mounted on the funnel and rigidly secured thereto by an outer metal shell or ring surrounding and hermetically sealed to the rim of the face plate.

In assembling the parts the sandwich supporting frame and the funnel are assembled as a unit and the sandwich mounted and adjusted therein. The face plate and its surrounding outer shell are also assembled and sealed together as a unit. Thereafter the face plate with its outer shell is telescoped with the outer flange of the sandwich frame. This brings the face edges of the said shell and flange together, after which they are hermetically sealed together along said edges. This permits the face plate to be removed thereafter when necessary by first cutting off the sealed edge portion of said flange and shell and also permits the parts to be reassembled and rescaled. The face plate and said outer shell can be hermetically sealed together by various means or methods as hereinafter pointed out. The funnel and the sandwich frame can also be sealed by similar methods, as will appear hereinafter.

Referring to the accompanying drawings:

Fig. l is a part sectional view of the assembled tube in an upright position with its axis vertical;

Fig. 2 is a fragmentary view on a larger scale showing a modified form of means for securing the face plate to the funnel;

Fig. 3 is a similar view taken at a point diametrically opposite from that of Fig. 2, and also showing certain modified means for sealing the parts together;

Fig. 4 is a front view of the clamping device shown in Fig. 3;

Fig. 5 is a fragmentary front view of the clamping device shown in Fig. 2; and

Fig. 6 is a fragmentary view similar to Fig. 3 showing further modification of the means for securing the parts together.

The picture tube as illustrated is a color television cathode ray tube comprising a funnel-shaped body 10 made of glass or metal and herein referred to as the funnel, and a face plate 11 made of glass or other transparent material. The funnel 10 has a tubular extension 12 at its smaller end to receive the usual electron guns. The wide end of the tunnel is formed with an annular rim 13 providing a cylindrical exterior surface when the funnel is circular in cross section. The funnel may be substantially rectangular or other non-circular shape in cross section. Mounted within the upper end of the funnel or between the latter and the face plate, is the sandwich 14 or grid assembly, which may be of conventional or known construction including a shadow mask 15 formed with a multiplicity of perforations through which the cathode beams 16 are propagated and directed to the sensitized plate or phosphor 17.

The sandwich is mounted on a supporting frame 20. Locating pins 21 projected in openings formed into the frame 24 maintain the sandwich in its adjusted position horizontally and rotatively relative to the frame 20. Leveling screws 22 serve for adjusting and leveling the sandwich into its position perpendicular to the am's 23 of the tube. The frame 20, which may be made of sheet metal, is formed with a horizontal annular body portion 2 3 and the connecting portion 25, the latter being in cross section in the form of an inverted U extending upwardly from the body 24 and shaped to fit over the funnel rim 13, the outer portion 26 of said extension being of cylindrical form and bearing against the outer vertical surface of the funnel rim 13. This outer flange portion 26 of the frame 20 may be hermetically sealed to the adjoining vertical surface of the funnel rim 13 and asa'nsse r also extends downward a substantial distance below the funnel rim 13. The hermetic seal between the rim 13 and flange 26 may be in the form of a glass-to-metal seal or a suitable cement or bonding material may be interposed between the juxtaposed surfaces of thefunnel rim and the'flange 26. A glass soldering method may be employed if desired. As shown in Fig. 3, an annular gasket 2? of rubber, rubber composition or'the like, may be interposed between the top surface of the funnel and the U shaped connecting part 25 of the frame 29, thereby forming a hermetic seal between said frame and the funnel. g

A means for clamping the face plate, 11 to the funnel as illustrated in Figs.'2 to 4, comprises a clamping device including a screw-threaded rod 36 pivoted at 31 to a bracket 32 attached to a metal shell 46 (presentlyto be described) and a wing nut 34 threaded on the rod 36. The rod extends downwardly through an opening in a bracket 36 attached .by means of a band 37 to the funnel ill. 1 7

At a point onthe opposite side of the funnel from the clamping device 3d, the outer shell 4% is slitted to form a tongue 38 (Figs. 3 and 4). When the face plate and funnel are in assembled relation, the tongue 38 isbent inward by a suitable tool to extend through an opening 41 in the flange 25 and engage the tapered outer surface of the funnel, thereby holding the shell 40 in position. The wing nut 34 can then be operated to draw the shell 4% downward and tighten it in position. A sealing gasket 39 may be interposed between the frame Ztl and the lower edge of the face plate (Figs. 2 and 3) and thereby provide a hermetic seal between said parts. If a sealing gasket 27 is used as in Fig. 3, the'operation of the clamp as just described serves also to form a hermetic seal between the funnel and the frame 2l.- A pad '42 of resilient compressible'material may be interposed between the tongue 38 and the funnel to maintain a continuous downward elastic pull on the shell 4t) for main- 7 taining the seal. 7

The metal shell fit) comprises an upwardlyconvergent or tapered upper portion e fi'which provides an endless band surrounding the correspondingly tapered marginal portion 45 of the face plate. The lower half of the shell is substantially cylindrical and surrounds the outer flange 26 'of the sandwich frame 24 in intimate contact therewith when the parts are assembled. The shell' it as shown in Figs. 1' to 3, is hermetically sealed to the face plate by a ring gasket 47 interposed between'part 44 of the shell and the rim 4:? of the face plate. V 7

Other methods of attaching and sealing the shell d to the faceplate maybe employed. As shown for example, in Fig. 6, the metal shell 4%; and the face plate have their opposite'surfaces in intimate contact and may be hermetically sealed together by a glass-to-metal seal. An alternative sealing method consists in the use of a suitable cement or bonding material between the juxtaposed'surfaces of thejshell and face plate. A glass soldermethod may also be used for uniting and sealing the shell 48 and face plate. 7

in practice the three composite units comprised in a complete picture tube, namely, the funnel with the frame sealed thereto, the grid assembly or sandwich, and the plate may then be hermetically sealed together in various ways as follows.

By placing a ring gasket 39 between the rim of the face plate and the adjacent surface of the frame 20 and 4 drawing the parts together by the clamping device 3%, 34, as heretofore described, a hermetic seal is formed between the funnel and face plate.

Another method of hermetically sealing the funnel and face plate together consists in soldering together the adjoining free edges 50 of the shell 46 and flange 26 by a solder 51 (Fig. l). The solder should have a melting and fusing temperature below the maximum temperature that can be used without harm to the sandwich or grid assembly, and above the temperature that is reached during the so-called bakeout during evacuation.

A further method of sealing the funnel and'face plate together consists in fusing and welding together the edges st of the shell and frame 20. In practicing .this method some means should be provided to prevent the heat from being conducted through the metal parts to an extent to impair the seal of metal to the glass or to cause injury to the grid assembly.

Fig. 6 illustrates still another method andmeans for sealing the funnel and face plate together. For this purpose a ring gasket 53 of rubber composition or the like is used as a seal.

The depending flange portion 26 of the frameZtl is in this instance extended beyond the edge of the shell 4t} and spun around the gasket 53 to form a bead 54, thereby compressing the gasket and completing the seal.

It will be seen that with each of the above constructions and methods for sealing the face plate to the funnel, these parts may be separated without difficulty if it becomes necessary to remove the face plate after the seal has been made. Thus, when the sealing gasket 39 is used, the seal may be broken and the parts separated by loosening the clamp 30, 34. When the parts are either soldered or welded together, the seal may be broken by cutting the two metal parts around their periphery, close to the edges 50, permitting the face plate to be withdrawn from the funnel. With the Fig. 6 construction, the bead 54 can be unwrapped and the seal thereby broken. After the seal has been broken in any of the above constructions, the

parts may be reassembled and rescaled in the same man ner as in the original assembly.

Modifications may be resorted to within the spirit and scope of the appended claims.

I claim:

1. A television tube envelope comprising a tapered hollow body, the rim portion of said body at the wide end thereof being extended in the direction of the axis of said body in tubular form, a face plate forming a closure for the wide end of said body, a connecting frame interposed between the adjoining rim surfaces of said face plate and body and formed with a tubular flange portion overlying and in contact with the'exterior surface of the said tubular rim of said body throughout substantially the entire extent of said exterior surface, a shell surrounding the face plate, the connecting frame comprising an annular body protruding inwardly from the inner surface of said rim portion of the tapered body and extending circumferentially of said inner surface, and means for securing the shellto the face plate, said shell having a tubular flange portion telescoped with and removably connected to the said flange portion of the connecting frame and thereby providing means for removably attaching the face plate to the said hollow body..

2. The television tube envelope as set forth in claim 1, and including means sealing together the juxtaposed surfaces of said frame and hollow body and forming a hen metic seal between the said hollow body and frame, means for sealing together the juxtaposed surfaces of the said face plate and shell and thereby forming a hermetic. seal between the face plate and said shell, and means forming a hermetic seal between said flange portions of the frame and shell.

3. The envelope defined in claim 2, the said means for sealing said flange portions together comprising a ring gasket extending along the edge of one of said flange portions, the other said flange portion having an extension wrapped around the gasket and forming a bead.

4. The envelope defined in claim 1, the said flange portions of the frame and shell having their free edges substantially together, and means for hermetically sealing said flange portions together with the seal extending along said free edges throughout their circumferences and confined to the said free edge portions, the edge portions with the seal being removable and thereby leaving the face plate and shell free for removal from the said frame and hollow body.

5. The envelope as defined in claim 4, the said sealing means consisting of a solder extending along and sealing said free edges together.

6. The envelope as defined in claim 4, the said free edges being Welded together.

7. A television tube envelope comprising a substantially funnel-shaped body, a frame having a peripheral portion substantially U-shaped in cross section embracing the rim of said body, a face plate, a shell surrounding and attached to the rim of the face plate and extended beyond the said rim in the form of a flange in telescopic engagement with said peripheral portion of the said frame, and means forming annular hermetic seals between said frame and funnel body, between said shell and face plate and between said shell and frame, each of said seals extending in sealing contact with the parts sealed thereby throughout the circumference of said sealed parts, said seals thereby hermetically sealing the face plate to the funnel body.

8. The combination set forth in claim 7, the shell and frame having free edges substantially together, the seal between the shell and frame extending along said free edges and being confined substantially to said edges, whereby separation of the funnel body and face plate is permitted by first removing the sealed edge portions of the shell and frame.

9. A television tube envelope comprising a funnel shaped body which when in an upright position with its Wide end uppermost and its axis vertical, has its upper edge in a horizontal plane, the rim portion of the funnel at said wide end being in the form of a cylindrical flange, a frame including a peripheral portion overlying the upper edge of the said body and formed with a cylindrical flange portion projecting downwardly over the exterior surface of the flange on said funnel body, the frame comprising an inner portion in the form of an annular flange extending along the inner surface of the funnel shaped body with the major surface of the flange lying substantially in a horizontal plane, a face plate overlying the said frame, and connecting means between the face plate and said frame comprising a cylindrical flange member extending downward over the flange portion of said frame in telescopic relation therewith, and means for removably attaching and sealing the flange portions of said frame and connecting means together.

10. The television tube envelope defined in claim 9, the said attaching means comprising a seal extending along the lower margins of said telescoped parts and confined to the said lower margins whereby the face plate is removably attached to the said body and separable by severing said lower margins.

11. A television tube envelope comprising a funnelshaped glass body, the wide end of the funnel comprising a rim having its inner and outer surfaces parallel with the axis of the funnel, a sheet metal frame including a peripheral portion substantially U-shaped in cross section and embracing the rim of the funnel, said peripheral portion being shaped to conform to the shape of the rim and having that portion of its inner surface on the inner side of the rim in contact with the rim throughout substantially the entire extent of said inner surface portion, said peripheral portion forming a flange covering the entire exterior surface of the funnel rim and extending beyond said rim in a direction parallel with the axis of the funnel, and a glass-to-metal seal sealing the said frame to the funnel, a face plate, a metal shell surrounding and connected to the rim of the face plate, said shell being extended beyond the rim of the face plate and thereby providing a flange extending parallel with the axis of the funnel and closely fitting and telescoping with the flange of said frame.

12. The television tube envelope defined in claim 11, the said flanges having their outer edges together, and means for hermetically sealing said edges together.

13. A television tube envelope comprising the construction defined in claim 11, and in combination therewith, means for securing and sealing the funnel and face plate together comprising a gasket between the rims of the funnel and face plate, and a hand-operated clamp attached to the funnel and said shell and operable to draw and seal the parts together.

References Cited in the file of this patent UNITED STATES PATENTS Re. 23,735 Olson Nov. 10, 1953 2,120,961 Beede June 21, 1938 2,178,826 Bowie Nov. 7, 1939 2,219,574 Fraenckel Oct. 29, 1940 2,293,529 Bedford Aug. 18, 1942 2,445,992 Beggs July 27, 1948 2,472,942 Drieschman et a1 June 14, 1949 2,506,687 Scherrer May 9, 1950 2,515,337 Clark July 18, 1950 2,562,163 Heinsch et al July 31, 1951 2,690,518 Fyler et a1 Sept. 28, 1954 2,691,457 Longacre Oct. 12, 1954 2,708,250 Day May 10, 1955 2,723,044 Barasch Nov. 8, 1955 FOREIGN PATENTS 52,590 France June 5, 1944 

